miR-204 functions as a tumor suppressor gene, at least partly by suppressing CYP27A1 in glioblastoma.

Gliomas are the most common type of malignant primary brain tumors in adults and exhibit a spectrum of aberrantly aggressive phenotypes. Despite advances in treatments during past decades, prognosis of the disease remains poor, with a median survival time of 12-14 months. Future studies on the molecular mechanism of the disease may provide the theoretical basis to identify new targets for effective therapies. The present study revealed that in glioblastoma cells, the overexpression of cytochrome P450, family 27, subfamily A, polypeptide 1 (CYP27A1) promoted proliferation, while silencing of CYP27A1 inhibited proliferation, without affecting migration and invasion. CYP27A1 protein was upregulated in glioblastoma tissues, indicating that CYP27A1 is an oncogene. The downregulation of specific microRNAs (miRNA) may contribute to the upregulation of oncogenes in glioblastoma. A common strategy was used to predict target miRNAs of CPY27A1 using the miRanda algorithm. miR-211 and miR-204 could target the 3'untranslated region of CPY27A1 mRNA. Additional studies confirmed that the overexpression of miR-204 inhibited CPY27A1 expression in glioblastoma cells. Finally, it was identified that miR-204 was downregulated in glioblastoma and that its overexpression inhibited proliferation, migration and invasion in glioblastoma cells. Thus, it was concluded that miR-204 functions as a tumor suppressor gene, at least partly by suppressing CYP27A1 in glioblastoma.